JP2000047604A - Manufacture of magnetic display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a manufacture of a magnetic display panel which facilitates temperature control and can be disposed of safely without any damage to environment and any harm to health. SOLUTION: The peripheral edge part 2a of a core storage body 2 made of olefin-based synthetic resin is raised to form a recessed part 6 inside and a paper-made core block having many independent cells 3 is arranged in the recessed part 6, adhered to the recessed part 6, and then a honeycomb core is filled with plastic dispersed liquid 5 containing magnetic particles. Further, an adhesive is applied to the reverse side of a surface plate 1 made of olefin- based synthetic resin provided on the opposite side from the core storage body 2 across the core block and this is adhered to the opening surface of the core block to charge the plastic dispersed liquid 3 in each cell 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a magnetic display panel mainly used for drawing by infants, wherein a special material is used for a core block and members for sealing the core block from both sides. The present invention relates to a method of manufacturing a magnetic display panel manufactured by a method completely different from the conventional method.

[0002]

2. Description of the Related Art As a drawing board for infants, a honeycomb core having a large number of hexagonal cells is sealed between a transparent drawing substrate and a facing material, and magnetic particles are placed in each of the cells. There is known a magnetic picture plate in which a plastic dispersion liquid containing liquid is sealed.

[0003] This is because a magnetic field is applied to the dispersion liquid by bringing the tip of a magnetic pen into contact with a drawing surface to cause magnetic particles sunk at the bottom to float on the drawing surface, thereby causing a difference in contrast between the dispersion medium and the magnetic particles. By displaying a picture or a character on the drawing surface by using, and by moving an eraser bar provided with a magnet or the like under the core housing, the floating magnetic particles are settled again to erase the picture or the character.

[0004] By the way, the plastic dispersion liquid containing magnetic particles is sealed in each cell of the honeycomb core by bonding both open end faces of the honeycomb core to a substrate and a face material. Specifically, the substrate, the face material, and the honeycomb core are all made of vinyl chloride, and the thermoplastic core is used to heat the honeycomb core to a softening point and then melt the opening end faces of the cells of the honeycomb core ( Crushing) and bonding the substrate and the face material, and applying an adhesive to the back side of the face material, drying the adhesive, pressing the face plate against the open end face of the honeycomb core, heating and melting the adhesive. Is considered to be a method of bonding the face material to the honeycomb core.

[0005]

However, in any of the above methods, if the heating temperature is too high, the honeycomb core itself is softened and its rigidity is deteriorated, so that the drawing surface is also deformed. The drawing substrate and the surface material themselves are also easily deformed by the heating temperature. On the other hand, if the heating temperature is low, poor adhesion is likely to occur.

[0006] If the substrate or the surface material is deformed unevenly, not only does the productability deteriorate, but also the magnetic pen does not slide smoothly, so it is difficult to draw and the operability is poor. In addition, if there is a defect in the bonding portion between the drawing substrate and the honeycomb core, adjacent cells in the defective bonding portion communicate with each other. In this case, as shown in FIG. 10A, a phenomenon occurs in which the liquid 21 sealed in the cell 20 leaks from the communicating portion between the deformed base material 22 and the partition wall 23 and flows into the adjacent cell 24. by the way,
When the plastic dispersion liquid 21 is poured into the honeycomb core, a part of the air is mixed and remains as bubbles 25 in the liquid. Large bubbles burst during the stirring and are released into the atmosphere. However, since the plastic dispersion liquid itself is an emulsion, the minute bubbles 25 remain in the dispersion liquid. When the magnetic display panel is used in a state where the partition walls 23 of the adjacent cells are broken, the pen pressure is changed when the magnetic pen is slid along the cells 24, or the magnetic display panel is moved in the horizontal direction. The plastic dispersion liquid 21 in the adjacent cells 20 comes in and out, and as shown in FIG. 2B, the minute bubbles 25 existing in the plastic dispersion liquid 21 in both cells 2 collide in the flow. As they gather, they grow larger. When the bubble grows and grows, it rises above the plastic dispersion liquid and adheres to the back side of the substrate 22. In such a state, the magnetic particles 26 are rubbed with a magnetic pen.
However, the air bubbles 25 hinder the magnetic particles 26 from floating to the back side of the base material 22. For this reason, the magnetic particles 26 cannot be visually recognized from the drawing surface, or are difficult to visually recognize, and the displayed drawing lines become unclear.

As described above, in the conventional manufacturing method, precision is required for temperature control, so that manufacturing is very troublesome.

Further, the conventional magnetic display panel made of vinyl chloride is used, discarded and incinerated at a low temperature.
Although toxic dioxins are being generated and research is ongoing, it is said to be a substance suspected of being an endocrine disruptor. In particular, magnetic display panels for infants, for which safety is required, are required to take stricter measures not only for safety during use but also for disposal after use.

The present invention solves the above-mentioned problems, facilitates temperature control and improves the production efficiency, and does not pollute the environment even after disposal, and provides safe disposal without harm to health. It is an object of the present invention to provide a method for manufacturing a magnetic display panel which can be performed.

[0010]

In order to solve the above-mentioned problems, a method of manufacturing a magnetic display panel according to the present invention comprises the following steps. (a) The peripheral portion of an olefin-based synthetic resin core housing is raised to form a concave portion inside, and a paper core block having a large number of independent cells is arranged in the concave portion. Adhering the concave portion with an adhesive (b) Then, filling the honeycomb core with a plastic dispersion liquid containing magnetic particles (c) Further, the honeycomb core is provided on the opposite side across the core block and the core block Apply an adhesive to the back side of the olefin-based synthetic resin face plate, adhere it to the opening of the core block, and enclose the plastic dispersion liquid in each cell.

The adhesive is a room temperature curing adhesive,
Alternatively, it is preferable to use an ultraviolet curable adhesive.

Preferably, the core block is a honeycomb core.

Further, when the face plate is bonded to the opening surface of the core block, the face plate is moved along the opening surface while being pressed against the opening surface of the core block by an appropriate means, or the face plate is bonded by an appropriate pressing method. It is preferable that the face plate is pressed against the opening surface of the core block and adhered by means.

[0014]

FIG. 1 shows a cross section of a magnetic display panel according to the present invention.
A honeycomb core 4 having a large number of cells 3 is hermetically sealed between the honeycomb core 4 and the core housing 2, and a plastic dispersion liquid 5 containing magnetic particles is sealed in each cell 3 of the honeycomb core 4.

In the above configuration, a magnetic pen (not shown)
By touching the drawing end (the surface of the core housing 2) or moving an eraser (not shown) provided with a magnet or the like slidably disposed on the back side of the face plate 1 to the left or right.
By applying a magnetic field to the plastic dispersion liquid 5, the magnetic particles can be floated on the drawing surface or settled away from the drawing surface to display or erase pictures and characters on the drawing surface.

Next, a method of manufacturing the magnetic display panel A2 will be described with reference to FIGS.

First, as shown in FIG. 2, the magnetic display panel A includes a core housing 2, a core block (honeycomb core 4), a composition dispersion liquid 5, and a face plate 1.
These components will be described sequentially.

The core housing 2 is made of a transparent or translucent olefin synthetic resin, for example, a polyethylene synthetic resin such as PET (polyethylene terephthalate) or a polypropylene synthetic resin such as polypropylene, as shown in FIG. The concave portion 6 is formed inside the core housing 2 by raising the peripheral edge portion 2a. Such a shape can be obtained by ordinary vacuum molding. The thickness (height) of the core housing 2 is related to the honeycomb core 4 and will be described later.

The honeycomb core 4 is a water-resistant and oil-resistant paper member having a honeycomb structure having a large number of independent cells 3. Such a honeycomb core 4 has, for example, a large number of strips as shown in FIG. Adhesives 8 are applied alternately at regular intervals to the front and back surfaces of each of the paper pieces 7, and they are sandwiched between two paper pieces 9 of the same size as shown in FIG.
After bonding the strips of paper 7 and 9 that have been polymerized by heating, pressing, or the like, the whole can be obtained by pulling out and expanding the whole of the strip in the forward and backward direction as shown in FIG.

As shown in FIG. 5 (a), the adhesive 11 is applied to the drawing surfaces of a large number of paper sheets 10 alternately at regular intervals in a strip shape. After being sandwiched between two paper sheets 12 and polymerized, the paper sheets 10 and 12 polymerized by heating, pressing and the like are adhered,
As shown in FIG. 3B, it is also possible to cut the wire with a predetermined width in a direction perpendicular to the direction of application of the adhesive as shown by a line P, and to pull out and expand the cut piece in the same direction as described above. Obtainable. Of course, other configurations may be used.

The size of each cell 3 of the honeycomb core 4 is usually such that the maximum width is inscribed in a circle having a maximum width of 2.0 mm to 8.0 mm, and the thickness of the honeycomb core 4 is preferably 0.5 mm to 5.0 mm. . It is technically difficult to form a paper with a maximum width of 2.0 mm or less on paper, and it is not necessary to have a fine one for drawing for infants. It is difficult to control the rise and settling of all the magnetic particles in 3, and there is a possibility that unevenness may occur in drawing. If the thickness of the honeycomb core 4 is smaller than 0.5 mm, the face plate 1 is kept in a state in which the magnetic particles sink into the bottom of the cell 3.
If it is larger than 5.0 mm, the magnetic force of the eraser bar provided with a magnetic pen, a magnet or the like must be increased more than necessary. The upper end of the recess 6 of the core housing 2 is formed to be higher than the upper end of the honeycomb core 4 by a difference d (described later) as shown in FIG.

The face plate 1 is also made of an olefin-based synthetic resin. When the surface of the face plate 1 is used as a drawing surface, it is made transparent.

Next, the honeycomb core 4 is sealed between the core housing 2 having the above-described structure and the face plate 1 in the following manner, and the plastic dispersion liquid 5 containing magnetic particles is filled with the honeycomb core 4.
In each cell 3.

First, the honeycomb core 4 is housed in the recess 6 of the core housing 2 as shown in FIG. In this case, the adhesive 13 may be applied to the bottom surface of the concave portion 6 and then the honeycomb core 4 may be pressed against the surface. As the adhesive 13 for bonding the core housing 2 and the honeycomb core 4, an adhesive suitable for bonding an olefin-based synthetic resin and paper can be used. A thermosetting adhesive such as a modified olefin-based hot melt adhesive or an adhesive that cures at room temperature as described below may be used. From the viewpoint of preventing deformation, if a thermosetting adhesive is used, the core housing 2 constituting the drawing surface may be distorted due to heat. Therefore, a room temperature curing type is preferable.

Next, as shown in FIG.
Is filled with the sufficiently dispersed plastic dispersion liquid 5. As the plastic dispersion liquid 5, a magnetic field is applied to the dispersion liquid 5 by bringing the tip of the magnetic pen into contact with the drawing surface or moving the eraser bar, so that the magnetic particles float on the drawing surface or separate from the drawing surface. Anything can be used as long as it can sink or display pictures and characters on the drawing surface or erase them. As such a plastic dispersion liquid 5, a liquid in which magnetic particles, a fine particle thickener, and a colorant are mixed in a dispersion medium is known.

Examples of the dispersing medium include polar dispersing media such as water and glycols, and non-polar dispersing media such as organic solvents and oils. As the magnetic particles, particles of an oxide magnetic material such as black magnetite, γ-hematite, chromium dioxide, and ferrite, and particles of an alloy-based metallic magnetic material such as iron, cobalt, and nickel may be used. Examples of the fine particle thickener include silicic anhydride, hydrous calcium silicate, hydrous aluminum silicate, silica powder, diatomaceous earth, kaolin, clay, benite, etc. Ultra-fine calcium carbonate,
Ultrafine activated calcium carbonate, heavy calcium carbonate, hydrated basic magnesium carbonate, barium sulfate, and the like are known, and examples of the coloring agent include white pigments and dyes.

Since the upper end of the recess 6 of the core housing 2 is higher than the upper surface (opening surface) of the honeycomb core 4, the plastic dispersion liquid 5 containing magnetic particles in the recess 6 of the core housing 2 is formed. As shown in FIG. 3 (c), the liquid level of the plastic dispersion liquid 5 exceeds the upper surface of the honeycomb core 4 and
To the height of the upper end of the

Next, the face plate 1 is bonded and fixed on the honeycomb core 4. First, an adhesive is applied to the back surface of the face plate 1. The adhesive is preferably one that cures at room temperature in order to prevent deformation of the face plate 1, and an epoxy resin-based adhesive or a modified acrylic resin-based adhesive that cures by irradiation with ultraviolet light is suitable. Which to use may be determined depending on whether the bonding operation is performed in a short time or a long time, as described later.

Epoxy resins include various types such as a glycidyl ester type and a phenol borak type, in addition to an ebis bis type obtained by reacting bisphenol or a derivative thereof with shrimp chlorohydrin.
Any of these is an oligomer having two or more oxirane rings (epoxy groups) in the molecule. For curing at room temperature, there are many two-part types such as an epoxy-polyamide or a quick-curing epoxy obtained by combining an epoxy resin and a polymercaptan-based curing agent. Recently, one-part modified epoxy has been developed. I have. Epoxy-modified polyamines and the like can also be used as the water-curable epoxy. Epoxy resin also has good adhesion to almost all adherends and generally does not contain volatile solvents, so it hardly shrinks after curing, there is no thinning, whitening by plastics with solvents, It has features such as being able to adhere without cracks, and having excellent chemical resistance and moisture resistance.

The epoxy resin-based adhesive is fixed until the curing is completed, but the pressing may be performed at a contact pressure or the like, and the curing is generally completed by leaving at room temperature for 24 hours. When shortening the curing time, the composition is cured by heating at 60 to 100 ° C. for 30 to 60 minutes. Therefore, it is suitable for performing the bonding operation for a long time.

The UV-curable adhesive is a radical-polymerizable one which absorbs ultraviolet energy to cause a photopolymerization reaction and cures, and is of a radical polymerization type, such as unsaturated polyester, polyester acrylate, urethane acrylate, silicone acrylate, epoxy acrylate and the like. Oligomers,
The main components are a monomer and a benzoin ether-based, benzophenone-based, acetophenone-based, or thioxanthone-based photopolymerization initiator, to which various additives are added. In addition, radical addition type polyethylene thiol as the main component, and cation polymerization type epoxy resin /
Examples include those containing a photodegradable onium salt as a main component. Normally, ultraviolet light does not reach the mating surface of the materials to be bonded, but there is no problem since the face plate 1 is made of a transparent olefin resin material and transmits ultraviolet light.

It should be noted that the ultraviolet-curing adhesive is cured in seconds by irradiation of ultraviolet rays, so that the line can be automated and speeded up. One-component, no mixing is required. And a cured product having various physical properties such as flexibility, adhesion, and chemical resistance can be obtained. Therefore, it is suitable for performing the bonding operation in a short time.

Next, after applying an adhesive to the back surface of the face plate 1 as described above, the face plate 1 is attached to the core housing 2 as shown in FIG.
As shown in FIG. 3 (e), the face plate 1 is slowly slid along the opening surface of the honeycomb core 4 while pressing the face plate 1 against the opening surface of the honeycomb core 4 by an appropriate pressing means 15 such as a round bar or a plate. Let it. The pressing means 15 may be configured to roll. Thereby, the face plate 1 is bonded to the upper surface of the honeycomb core 4. Thereafter, if the excess plastic dispersion liquid 5 on the face plate 1 is removed, the plastic dispersion liquid 5 is sealed in each cell 3 of the honeycomb core 4.

In this case, since the bonding operation must be performed in a short time, it is preferable to use an ultraviolet curable adhesive as the adhesive.

However, the pressing means 1 shown by a dotted line in FIG.
6 may be fixed to the opening surface of the honeycomb core 4 by pressing and bonding. In this case, since it is not necessary to perform the bonding operation in a short time, it is preferable to use an epoxy resin-based adhesive as the adhesive rather than an ultraviolet-curable adhesive. When an epoxy resin-based adhesive is used, when the face plate 1 is pressed and fixed to the honeycomb core 4 by the pressing means 16, the work may be simple because the pressing may be performed at about the contact pressure.
It is preferable that the face plate 1 is not formed in a flat plate shape, but is formed in a dish shape in advance according to a step between the concave portion 6 and the upper end portion of the honeycomb core 4.

When the difference d between the upper end of the recess 6 of the core housing 2 and the upper end of the honeycomb core 4 is small, the core housing 2 is filled with the plastic dispersion liquid 5 and then formed into a cylindrical shape or the like. While the face plate 1 is pressed against the honeycomb core 4 by appropriate scraping means (not shown), sliding or rolling is performed at a relatively high speed along the opening surface of the honeycomb core 4 in the same manner as in FIG. Can be moved. As a result, the excess plastic dispersion liquid 5 that has passed over the upper surface of the honeycomb core 4 is removed from the concave portion 6 with the same effect as the frictional cutting of the powder. The dispersion liquid 5 is the cells 3 of the honeycomb core 4
Is filled in. Since the face plate 1 is adhered to the upper end of the honeycomb core 4 while pushing out the excess plastic dispersion liquid 5 by a rubbing operation, the outside air is obstructed by the dispersion liquid 5 to be interposed between the face plate 1 and the honeycomb core 4. Can not enter. Therefore, since air does not enter the inside of the honeycomb core 4, only the plastic dispersion liquid 5 is sealed in each cell 3 of the honeycomb core 4.

Of the above, the plastic dispersion liquid 5 is surely sealed by the pressing means, but the work can be performed quickly by the scraping means.

Incidentally, the plastic dispersion liquid 5 above the honeycomb core 4 is for preventing air from entering when the face plate 1 is bonded to the honeycomb core 4. Is an excess liquid that is not filled.If the excess liquid amount is too large, the resistance to the movement of the abrasion means at the time of abrasion increases, and the force of the wave when pressed by the abrasion means increases the honeycomb force. It becomes an element that deforms the shape of the core 4. For this reason, since the moving speed of the scraping means must be suppressed, the work cannot be performed quickly. Therefore,
As described above, it is preferable that the dimensional difference d between the honeycomb core 4 and the upper end of the recess 6 is smaller. The optimum value is about 0.01 mm, but it is preferably 0.1 mm or less as a value suitable for practical use. Of course, the case where the dimensional difference d is 0 mm is excluded. 0
It must be larger than mm.

The thickness of the honeycomb core 4 is 0.5 mm to 5.
If the thickness is smaller than 0.5 mm, the magnetic particles can be seen through the outside of the face plate 1 while sinking at the bottom of the cell 3. If the thickness is larger than 5.0 mm, the magnetic force of the magnetic pen or eraser can be reduced. Must be larger than necessary.
Among the above numerical values, when the thickness was about 0.5 mm to 1.5 mm, these conditions were best satisfied. As described above, the height of the concave portion 6 of the housing 2 is equal to the thickness of the honeycomb core 4 plus the dimensional difference d.

Incidentally, in order to enclose the plastic dispersion liquid 5 in each cell 3 of the honeycomb core 4, the core housing 2
After the honeycomb core 4 is bonded and fixed thereon, the plastic dispersion liquid 5
And then bonding the face plate 1 on the honeycomb core 5. Therefore, the thickness of the core housing 2 is larger than the thickness of the face plate 1, for example, the former is 0.
It is better to use 2 mm and the latter about 0.1 mm. The reason is that the core housing 2 constitutes a drawing surface, so that the thickness is better in order to make the surface smooth and not to bend at the time of drawing, whereas the face plate 1 is formed by scraping off the plastic dispersion liquid. This is because it is necessary to be flexible in order to adhere to the honeycomb core 4.

It is preferable that the width of the peripheral portion 2a of the core housing 2 be slightly larger. This is because when the peripheral portion 2a is also a margin for the peripheral portion of the face plate 1, the bonding strength between the core housing 2 and the face plate 1 is increased. This is because there is no extra play between them, and the positioning is easy, and mounting means such as drilling for fixing to the display means is easily provided.

Next, the manner of enclosing by abrasion is not limited to the above example. For example, as shown in FIG. 6, the peripheral edge 2a of the core housing 2 may be formed obliquely, or as shown in FIG.
a may have a two-stage structure, and may be formed in the same manner as the upper end portion of the middle portion 2 b and the upper end portion of the honeycomb core 4. In this case,
As shown in (b), plastic dispersion liquid 5 containing magnetic particles
Is filled up to the upper surface of the upper step 2c of the core housing 2,
Next, the face plate 1 is put on the upper surface of the honeycomb core 4. At this time, the peripheral portion 2a of the face plate 1 is
Polymerized into In this state, by operating the scraping means in the same manner as described above, the face plate 1
At the same time, the excess plastic dispersion liquid 5 is eliminated, and the plastic dispersion liquid 5 is sealed in each cell 3 of the honeycomb core 4.

As shown in FIG. 8, a state in which the honeycomb core 4 having the same thickness as the height of the recess 6 is housed and fixed in the recess 6 of the core housing 2 is higher than the height of the core housing 2. Alternatively, the face plate 1 may be bonded and fixed inside the panel housing 17 having a higher dimension. in this case,
When the plastic dispersion liquid 5 containing magnetic particles is filled in the panel housing 17, the liquid level of the plastic dispersion liquid 5 exceeds the upper surfaces of the core housing 2 and the honeycomb core 4 and the panel housing 17
To the upper end of the surrounding wall. Therefore, the face plate 1 is moved along the opening surface of the honeycomb core 4 by appropriate scraping means or pressing means in the same manner as described above, or is pressed against the opening surface of the honeycomb core 4 so that the plastic dispersion liquid 5 The liquid is pressed and adhered to the upper end surface of each cell 3 of the honeycomb core 4 in the above liquid, so that no air enters into the inside.
After bonding, excess plastic dispersion liquid 5 may be removed.

In the case of the above example, since the entire surface of the face plate 1 is flat and the peripheral portion 2a is not deformed, the adhesion to the honeycomb core 4 is also ensured. Further, since the height of the peripheral wall of the panel storage body 17 can be determined regardless of the height of the core storage body 2 or the like, the plastic dispersion liquid 5 filled therein can be sufficiently vibrated and stirred by raising the peripheral wall. As a result, it is possible to disperse air bubbles mixed during filling into the atmosphere to a very small degree.

The core block 6 sealed between the core housing 2 and the face plate 1 is not limited to the honeycomb core 4 having the cells 3 in a honeycomb shape. For example, cell 3
It may have a rectangular shape as shown in (a), or may have a shape in which the waveform is alternately continuous as shown in FIG. Further, as shown in FIG. 3 (c), the shape may be a diamond shape.

As described above, the honeycomb core 4 and the core housing 2 and the face plate 1 are bonded by an adhesive.
There is no need to precisely control the heating temperature, and the temperature control becomes easy, so that the production efficiency can be increased.

Further, since the honeycomb core 4 is made of paper,
Good adhesion to the core housing 2 and the face plate 1. For this reason,
The core housing 2 and the face plate 1 are firmly bonded to the honeycomb core 4. Therefore, the plastic dispersion liquid 5 is securely sealed in each cell 3, and can sufficiently withstand an impact such as an infant hitting or hitting with a magnetic pen, and can always draw a clear drawing line.

The core housing 2 and the face plate 1 of the magnetic display panel A are each made of an olefin-based synthetic resin containing no chlorine in the molecular composition, and the honeycomb core 4 is made of paper. Therefore, even if the magnetic display panel A becomes unnecessary and is disposed of after being discarded, it can be safely disposed without generating harmful substances such as dioxin.

Further, the magnetic display panel A itself manufactured by the above-described manufacturing method also has features not available in the related art.

That is, a child may hit or poke the drawing surface with a magnetic pen during use. In this case, the impact of the magnetic pen is received by the core housing 2 and the honeycomb core 4, but since the honeycomb core 4 is made of relatively flexible paper and has an effect of becoming a cushion when subjected to the impact, Is absorbed by the deformation of the honeycomb core 4 and the impact force does not concentrate on one point, so that the possibility that a hole is formed in the core housing 2 is small. In addition, since the deformation is such that a part of the core housing 2 bends into a curved surface and is not a deformation that bends at an angle as in the conventional case, the core housing 2 and the honeycomb core 4 return to their original shapes after the deformation. It's easy to do. Then, after the impact is applied, the core housing 2 is restored to the original planar shape by the inherent elasticity, and the deformed portion of the honeycomb core 4 easily returns to the original shape with the help of this restoring force.

[0051]

According to the first aspect of the present invention, the honeycomb core and the core housing body / face plate are bonded with an adhesive, so that it is not necessary to control the heating temperature finely, and the temperature management becomes easy. The production efficiency can be increased.

Moreover, since the honeycomb core is made of paper, the adhesive for bonding the face plate and the honeycomb core permeates the fibers on the end face of the opening of the honeycomb core. Therefore, the face plate and the honeycomb core are firmly bonded. Therefore, the plastic dispersion liquid is reliably sealed in each cell, and can sufficiently withstand an impact such as an infant hitting or hitting with a magnetic pen, and can always draw a clear drawing line.

The core housing and the face plate of the magnetic display panel are each made of an olefin-based synthetic resin, and the honeycomb core is made of paper. Therefore, even if the magnetic display panel manufactured by the manufacturing method according to the present invention is incinerated after being discarded, it does not generate harmful substances such as dioxin, so that it does not pollute the environment or harm health. , Can be safely disposed of. Therefore, it is most suitable as a magnetic display panel used for drawing of infants.

Further, since the magnetic display panel has a paper core block which serves as a cushion when subjected to an impact inside the drawing surface, the magnetic display panel is deformed by the impact of a magnetic pen or the like. Easy to return to. Therefore, clear drawing lines can always be drawn, and use can be continued for a long time.

According to the second aspect of the present invention, since the adhesive is a room-temperature-curable adhesive, there is no need to heat the core housing, so that the core housing itself does not deform. Therefore, the sliding of the magnetic pen at the time of drawing becomes smooth, and the degree of perfection as a product is high.

According to the third aspect of the present invention, since the adhesive is of an ultraviolet curing type, it is cured in seconds, so that the bonding operation can be performed quickly.

According to the fourth aspect of the present invention, since the core block is a honeycomb core, the core block having the most stable production and the highest strength can be obtained.

According to the fifth aspect of the invention, in bonding the face plate to the opening surface of the core block, the face plate is moved along the opening surface while pressing the face plate against the opening surface of the core block by an appropriate means. Therefore, the bonding operation can be performed quickly.

According to the sixth aspect of the present invention, when the face plate is bonded to the opening surface of the core block, the face plate is pressed against the opening surface of the core block by an appropriate pressing means and bonded. Since the face plate can be securely adhered to the core block in the inside and the peripheral edge of the face plate can be adhered without being deformed, the surface of the face plate can be formed to be closer to a flat surface.

[Brief description of the drawings]

FIG. 1 is a sectional view of a magnetic display panel according to the present invention.

FIG. 2 is a perspective view simply showing a method of manufacturing the magnetic display panel.

3 (a), (b), (c), (d), and (e) are explanatory views of a method for manufacturing a magnetic display panel according to the present invention.

FIGS. 4 (a), (b) and (c) are explanatory views of a manufacturing mode of a honeycomb core.

FIGS. 5 (a) and 5 (b) are explanatory views of another embodiment of a honeycomb core in a manufacturing mode.

FIG. 6 is a longitudinal sectional view of another example of the core housing.

FIGS. 7 (a) and 7 (b) are explanatory views of a mode of enclosing a plastic dispersion liquid of another example.

FIG. 8 is an explanatory view of a mode of enclosing a plastic dispersion liquid according to still another example.

FIGS. 9 (a), (b) and (c) are explanatory views of a manufacturing mode of another example of the honeycomb core.

10 (a) and 10 (b) are explanatory diagrams of a bubble growth mode when the cells of the honeycomb core communicate with each other.

[Explanation of symbols]

 A magnetic display panel 1 face plate 2 core housing 3 cell 4 honeycomb core 5 plastic dispersion liquid 6 recess

Claims (6)

[Claims] 1. A method for manufacturing a magnetic display panel, comprising the following steps. (a) The peripheral portion of an olefin-based synthetic resin core housing is raised to form a concave portion inside, and a paper core block having a large number of independent cells is arranged in the concave portion. Adhering the concave portion with an adhesive (b) Then, filling the honeycomb core with a plastic dispersion liquid containing magnetic particles (c) Further, the honeycomb core is provided on the opposite side across the core block and the core block Apply an adhesive to the back side of the olefin-based synthetic resin face plate, adhere it to the opening of the core block, and enclose the plastic dispersion liquid in each cell. 2. The method for manufacturing a magnetic display panel according to claim 1, wherein the adhesive is a room temperature curing type adhesive. 3. The method for manufacturing a magnetic display panel according to claim 1, wherein the adhesive is an ultraviolet-curable adhesive. 4. The method according to claim 1, wherein the core block is a honeycomb core. 5. The magnetic display according to claim 1, wherein, when the face plate is bonded to the opening surface of the core block, the face plate is moved along the opening surface while being pressed against the opening surface of the core block by an appropriate means. Panel manufacturing method. 6. The method for manufacturing a magnetic display panel according to claim 1, wherein, when bonding the face plate to the opening surface of the core block, the face plate is pressed and bonded to the opening surface of the core block by an appropriate pressing means.